Folding electronic device

ABSTRACT

A folding electronic device having a first housing and a second housing foldably connected through a hinge mechanism. The folding electronic device includes a first hinge cylinder integrated with the first housing, a second hinge cylinder integrated with the second housing, and a pipe inserted in one end of the first hinge cylinder and in one end of the second hinge cylinder to foldably connect the second housing to the first housing. The folding electronic device further includes a wiring member inserted through the pipe to connect a first electronic component mounted in the first housing and a second electronic component mounted in the second housing, a first gasket provided between the pipe and the first hinge cylinder, a second gasket provided between the pipe and the second hinge cylinder, and a hinge cap for tightly closing the other end of the first hinge cylinder

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a folding electronic devicesuch as a folding mobile phone, and more particularly to a waterproofstructure for a folding electronic device. It should be noted that theterm of “mobile phone” used in this description and claims includes aPersonal Handyphone System (PHS) phone.

2. Description of the Related Art

A folding mobile phone has a structure such that a first housing havingan input portion and a transmitting portion and a second housing havinga display portion and a receiving portion are foldably connected witheach other through a hinge mechanism. As to an electrical structure, anelectronic component mounted in the first housing and an electroniccomponent mounted in the second housing are connected with each otherthrough a cable or a flexible printed wiring board. The hinge mechanismhas not only an original function of foldably connecting the firsthousing and the second housing, but also a function of maintaining thedistance and angle between a receiver and a microphone as required foruse as a telephone in consideration of the ergonomically positionalrelation therebetween.

A mobile phone usable anywhere at any time is essential in the modernsociety, and it is desired to provide a folding mobile phone having awaterproof structure, which can be used even in the rain, after seabathing, or in the bathroom of a spa, for example. However, thewaterproof structure for the folding mobile phone has not yet been putto practical use because the waterproof structure for the hingemechanism is difficult to realize. The hinge mechanism is required tohave a high degree of waterproofness because of its requiredopening/closing durability, e.g., a durable lifetime corresponding to atleast one hundred thousand of opening/closing operations. Further, it isalso necessary to consider deterioration in waterproofness due to thedeformation or damage to a case of the mobile phone when a drop impactis applied. Thus, the object can be achieved only for a heavy-dutyproduct such as an outdoor style product.

Japanese Patent Laid-open No. 2002-319771 discloses a folding portablecommunication terminal capable of effecting a dripproof function for acontact between a flexible printed wiring board and a connector. Thisfolding portable communication terminal has a structure such that aninput portion and a display portion are foldably connected with eachother through a hinge and that an electronic component mounted in theinput portion and an electronic component mounted in the display portionare connected with each other through a flexible printed wiring board.The input portion and the display portion are respectively provided withinsertion portions for allowing the insertion of the flexible printedwiring board in the vicinity of the hinge. At least one of theseinsertion portions is provided with a pair of packings abutting againstthe front and rear surfaces of the flexible printed wiring board.

In the folding portable communication terminal as described in theabove-cited publication, a simple dripproof structure is provided bymaking the pair of packings abut against the front and rear surfaces ofthe flexible printed wiring board. However, any completely waterproofstructure is not given for the hinge portion for pivotably connectingthe input portion and the display portion. For example, in the case thatthe portable communication terminal is immersed in the water, the entryof water into the device cannot be completely prevented.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a foldingelectronic device having a completely waterproof structure.

In accordance with an aspect of the present invention, there is provideda folding electronic device including a first housing having anintegrally formed, first hinge cylinder having a first end and a secondend; a second housing having an integrally formed, second hinge cylinderhaving a first end and a second end; a pipe inserted in the first end ofthe first hinge cylinder and the first end of the second hinge cylinderto connect the first housing and the second housing so that the secondhousing is foldable with respect to the first housing; a wiring memberinserted through the pipe to connect a first electronic componentmounted in the first housing and a second electronic component mountedin the second housing; a first gasket provided between the pipe and thefirst hinge cylinder; a second gasket provided between the pipe and thesecond hinge cylinder; and a first hinge cap for tightly closing thesecond end of the first hinge cylinder.

Preferably, the folding electronic device further includes a tube havinga third gasket at one end and a fourth gasket at the other end. The tubeaccommodates the wiring member and is inserted through the pipe. Thethird gasket tightly seals a wiring leading portion of the firsthousing, and the fourth gasket tightly seals a wiring leading portion ofthe second housing. The wiring member includes a cable or a flexibleprinted wiring board. Preferably, the folding electronic device furtherincludes a first metal pipe inserted in the first end of the first hingecylinder, the first metal pipe having an inner circumferential surfacecoming into pressure contact with the first gasket, and a second metalpipe inserted in the first end of the second hinge cylinder, the secondmetal pipe having an inner circumferential surface coming into pressurecontact with the second gasket.

Preferably, the folding electronic device further includes a third hingecylinder integrated with the first housing, the third hinge cylinderhaving a first end and a second end; a hinge module having one endinserted in the second end of the second hinge cylinder and another endinserted in the first end of the third hinge cylinder; a third gasketprovided between the hinge module and the second hinge cylinder; and asecond hinge cap for tightly closing the second end of the third hingecylinder. The hinge module includes a case inserted and fixed in thethird hinge cylinder; a fixed cam plate accommodated in the case; amovable cam plate inserted in the second end of the second hingecylinder so as to be nonrotatable relative to the second hinge cylinder;a plurality of balls held between the fixed cam plate and the movablecam plate; a connecting shaft for connecting the case and the movablecam plate; and a coil spring accommodated in the case for biasing thefixed cam plate toward the movable cam plate.

In accordance with another aspect of the present invention, there isprovided a folding electronic device including a first housing having anintegrally formed, first hinge cylinder having a first end and a secondend; a second hinge cylinder having a wiring leading hollow shaft, afirst end, and a second end; a second housing engaged with the wiringleading hollow shaft of the second hinge cylinder so as to be rotatableabout the wiring leading hollow shaft; a pipe inserted in the first endof the first hinge cylinder and the first end of the second hingecylinder to connect the first housing and the second housing so that thesecond housing is foldable with respect to the first housing; a wiringmember inserted through the pipe to connect a first electronic componentmounted in the first housing and a second electronic component mountedin the second housing; a first gasket provided between the pipe and thefirst hinge cylinder; a second gasket provided between the pipe and thesecond hinge cylinder; a first hinge cap for tightly closing the secondend of the first hinge cylinder; and a third gasket provided between thewiring leading hollow shaft of the second hinge cylinder and the secondhousing.

The above and other objects, features and advantages of the presentinvention and the manner of realizing them will become more apparent,and the invention itself will best be understood from a study of thefollowing description and appended claims with reference to the attacheddrawings showing some preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a partially cutaway, plan view of a folding mobile phonehaving a uniaxial hinge structure;

FIG. 1B is a side view of the mobile phone shown in FIG. 1A in itsfolded condition;

FIG. 2A is a plan view of a fixed input unit (first housing);

FIG. 2B is a left side view of FIG. 2A;

FIG. 2C is a right side view of FIG. 2A;

FIG. 3A is a partially cutaway, plan view of a folding mobile phonehaving a biaxial hinge structure;

FIG. 3B is a side view of the mobile phone shown in FIG. 3A in itsfolded condition;

FIG. 4 is a sectional view of a folding mobile phone according to afirst preferred embodiment of the present invention;

FIG. 5 is a sectional view of the mobile phone shown in FIG. 4 in itsfolded condition;

FIG. 6 is a sectional view of a hinge module;

FIG. 7A is a sectional view of a hinge module having a waterproofstructure for a fixed case;

FIG. 7B is a sectional view of a hinge module having another waterproofstructure for a fixed case;

FIG. 8 is a sectional view of a folding mobile phone according to asecond preferred embodiment of the present invention;

FIG. 9A is a side view of a tube having bent portions;

FIG. 9B is a side view of a straight tube;

FIG. 9C is an enlarged sectional view of an encircled portion P shown inFIG. 9B;

FIG. 10 is a sectional view showing a waterproof structure of a gasketapplied to the wiring leading portion of the second housing shown inFIG. 8;

FIG. 11 is a sectional view of a folding mobile phone according to athird preferred embodiment of the present invention;

FIG. 12 is a sectional view of a folding mobile phone according to afourth preferred embodiment of the present invention;

FIG. 13 is a sectional view of a folding mobile phone according to afifth preferred embodiment of the present invention;

FIG. 14 is a sectional view of a folding mobile phone according to asixth preferred embodiment of the present invention;

FIG. 15 is a sectional view of the mobile phone shown in FIG. 14 in itsfolded condition;

FIG. 16A is a sectional view of a movable housing (second housing)having a vertically compressed gasket;

FIG. 16B is a sectional view of a movable housing having a horizontallycompressed gasket;

FIG. 17A is a sectional view of a fixed housing (first housing) having avertically compressed gasket;

FIG. 17B is a sectional view of a fixed housing having a horizontallycompressed gasket;

FIG. 18A is a bottom plan view showing the layout of the gasket providedin the movable housing shown in FIG. 16A or 16B;

FIG. 18B is a bottom plan view showing the layout of the gasket providedin the fixed housing shown in FIG. 17A or 17B; and

FIG. 19 is a sectional view of a fixed housing having a waterproofstructure for an antenna.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1A, a partially cutaway, plan view of a folding mobilephone having a uniaxial hinge structure is shown. FIG. 1B is a side viewof the mobile phone shown in FIG. 1A in its folded condition. FIG. 2A isa plan view of a fixed input unit (first housing) of the mobile phone.FIG. 2B is a left side view of FIG. 2A, and FIG. 2C is a right side viewof FIG. 2A. As shown in FIG. 1A, a first housing (fixed housing) 2having an input portion 4 and a second housing (movable housing) 8having a display portion 10 such as an LCD are foldably connected witheach other through a hinge mechanism 14.

As shown in FIG. 2A, the first housing 2 further has a transmittingportion 6 accommodating a microphone and an antenna accommodatingportion 7 accommodating an antenna. As shown in FIG. 1A, the secondhousing 8 further has a receiving portion 12 accommodating an earphone.Referring to FIG. 3A, a partially cutaway, plan view of a folding mobilephone having a biaxial hinge structure is shown. FIG. 3B is a side viewof the mobile phone shown in FIG. 3A in its folded condition. As shownin FIG. 3A, a second housing 8 is foldably connected through a hingemechanism 14 to a first housing 2 and mounted thereto so as to berotatable about a wiring leading hollow shaft 18.

Referring to FIG. 4, a sectional view of a folding mobile phoneaccording to a first preferred embodiment of the present invention isshown. FIG. 5 is a sectional view of the mobile phone shown in FIG. 4 inits folded condition. The first housing 2 is integrally formed with apair of hinge cylinders 20 and 22. The second housing 8 is integrallyformed with a hinge cylinder 24 fitted between the hinge cylinders 20and 22 of the first housing 2. These hinge cylinders 20, 22, and 24 havesubstantially the same inner diameter. The first and second housings 2and 8 are formed of resin, for example. A pipe 26 is inserted in one endportion of the hinge cylinder 20 and in one end portion of the hingecylinder 24. A hinge module 44 is inserted in the other end portion ofthe hinge cylinder 24 and in the hinge cylinder 22. Thus, the secondhousing 8 is foldably connected to the first housing 2.

A wiring member 28 such as a cable or a flexible printed wiring board isinserted through the pipe 26 to connect an electronic component mountedin the first housing 2 and an electronic component mounted in the secondhousing 8. Reference numeral 30 denotes a wiring leading opening of thefirst housing 2, and reference numeral 32 denotes a wiring leadingopening of the second housing 8. The pipe 26 is preferably formed ofmetal such as stainless steel. Alternatively, the pipe 26 may be formedof resin.

Two gaskets 34 and 36 are provided between the outer circumferentialsurface of the pipe 26 and the inner circumferential surface of thehinge cylinder 20. Two gaskets 38 and 40 are also provided between theouter circumferential surface of the pipe 26 and the innercircumferential surface of the hinge cylinder 24. Further, a hinge cap42 is bonded to the other end of the hinge cylinder 20, thereby tightlyclosing the other end of the hinge cylinder 20. In this manner, the fourgaskets 34 to 40 are provided between the outer circumferential surfaceof the pipe 26 and the inner circumferential surfaces of the hingecylinders 20 and 24, so that this hinge portion can provide a rotatablewaterproof structure.

Thus, the right end of the hinge cylinder 20 is tightly sealed by thetwo gaskets 34 and 36, and the left end of the hinge cylinder 20 istightly closed by the hinge cap 42, so that the entry of water into thefirst housing 2 can be prevented. Further, the left end of the hingecylinder 24 is tightly sealed by the two gaskets 38 and 40, so that theentry of water into the second housing 8 can be prevented.

The hinge module 44 has a case 46 inserted and fixed in the hingecylinder 22. The case 46 is integrally formed with a rotation preventionkey 48, and the hinge cylinder 22 is formed with a keyway. The rotationprevention key 48 of the case 46 is inserted into the keyway of thehinge cylinder 22, thereby nonrotatably mounting the case 46 to thehinge cylinder 22. The hinge module 44 has a rotating member 50rotatable relative to the case 46. The rotating member 50 isnonrotatably mounted to the hinge cylinder 24. More specifically, therotating member 50 is made nonrotatable relative to the hinge cylinder24 by a key structure 52 composed of a key and a keyway.

As shown in FIG. 5, the first housing 2 is integrally formed with aremoval prevention rib 56, and the case 46 is formed with a recess 57for engaging the upper end of the rib 56, thereby preventing rightwardremoval of the hinge module 44 from the hinge cylinder 22. A gasket 54is provided between the outer circumferential surface of the case 46 ofthe hinge module 44 and the inner circumferential surface of the hingecylinder 24, thereby providing a waterproof structure on the movableside of the hinge module 44.

The right end of the hinge cylinder 22 in which the hinge module 44 isinserted is tightly closed by a hinge cap 58, thereby making waterproofthe inside of the fixed case 46 of the hinge module 44. As shown in FIG.5, the first housing 2 is composed of a front case 2 a and a rear case 2b joined to the front case 2 a. A gasket 60 is mounted between thejoined surfaces of the front case 2 a and the rear case 2 b, therebytightly sealing the inside of the first housing 2. Such a tight sealingstructure will be hereinafter described in detail.

FIG. 6 shows a sectional view of the hinge module 44. The hinge module44 has the case 36 integrally formed with the rotation prevention key48, and also has a fixed cam plate 62 accommodated in the case 46. Thecase 46 and the fixed cam plate 62 are formed of resin. As mentionedabove, the case 46 is inserted and fixed in the hinge cylinder 22. Thehinge module 44 further includes a movable cam plate 64 formed of metaland a mounting member 66 formed of resin. The mounting member 66 isbonded to the movable cam plate 64. The mounting member 66 has a keyway68. The movable cam plate 64 and the mounting member 66 constitute therotating member 50.

A pair of balls 70 are held between the fixed cam plate 62 and themovable cam plate 64 so as to be spaced circumferentially 180° apartfrom each other. Recesses for accommodating the balls 70 are formed onthe opposed surfaces of the fixed cam plate 62 and the movable cam plate64. The case 46 and the rotating member 50 are connected together by aconnecting shaft 72 having a head 72 a. The connecting shaft 72 isriveted at its left end 74 as viewed in FIG. 6. A coil spring 76 isaccommodated in the case 46 to bias the fixed cam plate 62 toward themovable cam plate 64. The gasket 54 is mounted on the case 46 to therebyprevent the entry of water into the movable side of the hinge module 44as shown in FIG. 4.

The operation of the hinge module 44 will now be described. When thesecond housing 8 is rotated from a talking position toward a foldedposition to reach a first given position just before the folded positionby a given angle, e.g., 20°, the pair of balls 70 come intocircumferentially one end portions of the recesses of the movable camplate 64 and abut against inclined surfaces of the recesses.Accordingly, the biasing force of the coil spring 76 is converted into arotational force for rotating the movable cam plate 64 from the abovefirst given position to the folded position. As a result, the secondhousing 8 is rotated to the folded position and maintained at thisposition.

Conversely, when the second housing 8 is rotated from the foldedposition toward the talking position to reach a second given positionjust before the talking position by a given angle, e.g., 20°, the pairof balls 70 come into circumferentially other end portions of therecesses of the movable cam plate 64 and abut against inclined surfacesof the recesses. Accordingly, the biasing force of the coil spring 76 isconverted into a rotational force for rotating the rotating member 50from the above second given position to the talking position. As aresult, the second housing 8 is rotated to the talking position andmaintained at this position.

FIGS. 7A and 7B are sectional views of hinge modules 44A and 44B eachhaving a waterproof structure for a fixed case. As shown in FIG. 7A, thehinge module 44A has a case 46, and the right end of the case 46 istightly closed by an end cap 78. The end cap 78 is fixed to the case 46by adhesion or ultrasonic welding, for example. The other structures ofthis preferred embodiment are similar to those of the hinge module 44shown in FIG. 6.

As shown in FIG. 7B, a waterproof hinge case 82 is bonded to a case 46of the hinge module 44B. The right end of the case 46 is tightly closedby the waterproof hinge case 82. The other structures of this preferredembodiment are similar to those of the hinge module 44 shown in FIG. 6.In the hinge module 44A or 44B, the case 46 is tightly closed by the endcap 78 or the waterproof hinge case 82, thereby preventing the entry ofwater into the fixed case 46.

Referring next to FIG. 8, a sectional view of a folding mobile phoneaccording to a second preferred embodiment of the present invention isshown. In this preferred embodiment, the hinge portion including awiring member has a double-waterproof structure to improve thewaterproof reliability. More specifically, a wiring member 28 isaccommodated in a tube 84 integrally formed with gaskets 84 a and 84 b.The wiring leading opening 30 of the first housing 2 is tightly sealedby the gasket 84 a, and the wiring leading opening 32 of the secondhousing 8 is tightly sealed by the gasket 84 b. The tube 84 is formed ofa soft material such as silicone rubber.

The other structures of this preferred embodiment are similar to thoseof the first preferred embodiment. In this preferred embodiment, thespan S is set large, so as to reduce a torsional stress of the wiringmember 28 and thereby improve the durability. As the tube 84, apreliminarily bent tube as shown in FIG. 9A is used. Alternatively, abellows straight tube 85 as shown in FIG. 9B may be prepared and bent inmounting. The tube 85 is integrally formed at its opposite ends withgaskets 85 a and 85 b. FIG. 9C is an enlarged sectional view of anencircled portion P shown in FIG. 9B.

FIG. 10 is a sectional view showing a waterproof structure of the gasket84 b applied to the wiring leading opening 32 of the second housing 8. AC-shaped leaf spring 86 is provided in the tube 84 so as to apply apressure to the gasket 84 b in its normal direction, thereby making apressure contact of the gasket 84 b with the second housing 8 definingthe wiring leading opening 32. A similar waterproof structure isapplicable also to the wiring leading opening 30 of the first housing 2.

Referring next to FIG. 11, a sectional view of a folding mobile phoneaccording to a third preferred embodiment of the present invention isshown. In this preferred embodiment, the rotating member 50 of the hingemodule 44 is integrally formed with a hinge fixing hook 88. The hingefixing hook 88 is engaged with the hinge cylinder 24 to thereby preventaxial removal of the hinge module 44. Accordingly, this preferredembodiment does not include the removal prevention rib 56 employed inthe first and second preferred embodiments. Further, the third preferredembodiment includes two gaskets 54 and 54′ to improve the waterproofnessfor the hinge module 44.

Referring next to FIG. 12, a sectional view of a folding mobile phoneaccording to a fourth preferred embodiment of the present invention isshown. In this preferred embodiment, metal pipes 90, 92, and 94 formedof stainless steel or the like are inserted in the hinge cylinders 20and 24 to improve the waterproof accuracy. In the case that the housings2 and 8 are formed of resin, torsion or the like is prone to occur,possibly causing a reduction in waterproofness of the hinge portion. Tocope with this possibility, the metal pipes 90, 92, and 94 are insertedin the hinge cylinders 20 and 24 at positions where the gaskets 34 to 40and 54 are located according to this preferred embodiment. The gaskets34 to 40 and 54 are made to come into pressure contact with the metalpipes 90, 92, and 94, thereby providing an improved waterproofstructure. Thus, the object with which each gasket comes into pressurecontact is formed of metal, so that a dimensional change can be reducedto thereby improve the waterproof performance.

Referring next to FIG. 13, a sectional view of a folding mobile phoneaccording to a fifth preferred embodiment of the present invention isshown. This preferred embodiment is similar to the fourth preferredembodiment shown in FIG. 12 except the point that a gasket 96 is addedto the hinge module 44. Since the gasket 96 is added to the hinge module44, the entry of water into the fixed case 46 of the hinge module 44 canbe prevented. Accordingly, this configuration is effective in the casethat it is applied to the hinge module 44 whose case 46 has nowaterproof structure as shown in FIG. 6.

Referring next to FIG. 14, a sectional view of a folding mobile phoneaccording to a sixth preferred embodiment of the present invention isshown. FIG. 15 is a sectional view of the mobile phone shown in FIG. 14in its folded condition. The mobile phone according to this preferredembodiment has a biaxial hinge structure. That is, the biaxial hingestructure includes a substantially T-shaped hinge cylinder 100integrally formed with a hollow shaft 102 for leading a wiring member28. The second housing 8 is mounted to the first housing 2 so as to berotatable about the hollow shaft 102 of the hinge cylinder 100.

The hollow shaft 102 is engaged with the second housing 8, and anengaging portion therebetween is provided with a rugged cam 104, a snapring or nut 106, and a coned disc spring 108. Further, the engagingportion between the hollow shaft 102 and the second housing 8 isprovided with a gasket 110 for preventing the entry of water into thesecond housing 8. The other configurations of this preferred embodimentare similar to those of the first preferred embodiment shown in FIG. 4.

FIG. 16A is a sectional view of a second housing (movable housing) 8composed of a front case 8 a and a rear case 8 b joined to the frontcase 8 a, wherein the front case 8 a is formed of Mg alloy. In general,a resin case is low in strength. To increase the strength of the frontcase 8 a, the front case 8 a is formed of Mg alloy in this preferredembodiment. Further, the front case 8 a is integrally formed with a rib113, and the rib 113 vertically abuts against a gasket 112 providedbetween the joined surfaces of the front case 8 a and the rear case 8 b.Thus, the gasket 112 is retained in a vertically compressed condition.Alternatively, the front case 8 a may be formed of Al alloy or Zn alloy.

FIG. 16B is a sectional view of a second housing 8 according to anotherpreferred embodiment of the present invention, wherein the gasket 112 ishorizontally compressed. Also in this preferred embodiment, the frontcase 8 a is formed of metal such as Mg alloy. Further, the front case 8a is integrally formed with a rib 115, and the rib 115 horizontallyabuts against the gasket 112. Thus, the gasket 112 is retained in ahorizontally compressed condition. In each of the above preferredembodiments shown in FIGS. 16A and 16B, an elastic band 117 is bonded tothe outer peripheral surfaces of the front case 8 a and the rear case 8b joined together, thereby providing a double seal structure includingthe gasket 112 and the elastic band 117.

FIG. 17A is a sectional view of a first housing (fixed housing) 2composed of a front case 2 a and a rear case 2 b joined to the frontcase 2 a. The front case 2 a is formed of Mg alloy, and a double sealstructure including a gasket 60 and an elastic band 118 is adopted. Inthis preferred embodiment, the gasket 60 is retained in a verticallycompressed condition. FIG. 17B shows another preferred embodimentwherein the gasket 60 is retained in a horizontally compressedcondition. The other structures of this preferred embodiment are similarto those of the preferred embodiment shown in FIG. 17A.

FIG. 18A schematically shows the layout of the gasket 112 provided inthe second housing 8 shown in FIG. 16A or 16B. To provide a waterproofstructure having high reliability, it is preferable that anywaterproofed portions be minimized. In the second housing 8 shown inFIG. 18A, a plurality of screws 114 for fixing the front case 8 a andthe rear case 8 b are arranged outside of the gasket 112. FIG. 18Bschematically shows the layout of the gasket 60 provided in the firsthousing 2 shown in FIG. 17A or 17B. Also in this preferred embodiment, aplurality of screws 116 for fixing the front case 2 a and the rear case2 b are arranged outside of the gasket 60.

FIG. 19 is a sectional view of a first housing (fixed housing) 2 havinga waterproof structure for an antenna. In a conventional mobile phone,the antenna has a structure such that a separate component is mounted toa housing. Accordingly, an antenna mounting portion must be subjected toa waterproofing process in the conventional art. In the preferredembodiment shown in FIG. 19, the rear case 2 b of the first housing 2 isprojected to form an antenna accommodating portion 7 for accommodatingan antenna 138, so that the entry of water from the antenna mountingportion into the housing 2 can be completely prevented.

To improve the waterproofness of the first housing 2, the front case 2 ais formed of metal such as Mg alloy. Accordingly, to satisfy antennacharacteristics, the distance G between an antenna printed wiring board140 on which a matching circuit 142 is mounted and the front case 2 amust be set greater than or equal to a given distance, e.g., 3 mm. InFIG. 19, reference numeral 122 denotes a waterproof switch modulecomposed of a switch sheet 124, resin key-tops 126, switch depressingprojections 128, and a decorative panel 132. A printed wiring board 120is accommodated in the first housing 2, and this printed wiring board120 and the switch sheet 124 are connected with each other through aconnector 134 and a flexible printed wiring board 136.

While the present invention is applied to a folding mobile phone in theabove description, it should be noted that the applicability of thepresent invention is not limited to a folding mobile phone, but can beextended to a folding electronic device such as a personal digitalassistants (PDA) and a notebook personal computer (notebook PC).

According to the present invention, the gap between the pipe and thefirst hinge cylinder is tightly sealed by the first gasket, and the gapbetween the pipe and the second hinge cylinder is tightly sealed by thesecond gasket. Furthermore, the second end of the first hinge cylinderis tightly closed by the first hinge cap. Thus, the hinge portion of thefolding electronic device can be completely waterproofed. Such awaterproof effect at the hinge portion cannot be expected by thestructure disclosed in Japanese Patent Laid-open No. 2002-319771mentioned above.

The present invention is not limited to the details of the abovedescribed preferred embodiments. The scope of the invention is definedby the appended claims and all changes and modifications as fall withinthe equivalence of the scope of the claims are therefore to be embracedby the invention.

1. A folding electronic device comprising: a first housing having anintegrally formed, first hinge cylinder having a first end and a secondend; a second housing having an integrally formed, second hinge cylinderhaving a first end and a second end; a pipe inserted in said first endof said first hinge cylinder and said first end of said second hingecylinder to connect said first housing and said second housing so thatsaid second housing is foldable with respect to said first housing; awiring member inserted through said pipe to connect a first electroniccomponent mounted in said first housing and a second electroniccomponent mounted in said second housing; a first gasket providedbetween said pipe and said first hinge cylinder; a second gasketprovided between said pipe and said second hinge cylinder; a first hingecap for tightly closing said second end of said first hinge cylinder;and a tube having a third gasket at one end and a fourth gasket at theother end, said tube accommodating said wiring member and being insertedthrough said pipe; said third gasket tightly sealing a wiring leadingportion of said first housing, said fourth gasket tightly sealing awiring leading portion of said second housing.
 2. The folding electronicdevice according to claim 1, wherein said wiring member comprises acable or a flexible printed wiring board.
 3. A folding electronic devicecomprising: a first housing having an integrally formed, first hingecylinder having a first end and a second end; a second housing having anintegrally formed, second hinge cylinder having a first end and a secondend; a pipe inserted in said first end of said first hinge cylinder andsaid first end of said second hinge cylinder to connect said firsthousing and said second housing so that said second housing is foldablewith respect to said first housing; a wiring member inserted throughsaid pipe to connect a first electronic component mounted in said firsthousing and a second electronic component mounted in said secondhousing; a first gasket provided between said pipe and said first hingecylinder; a second gasket provided between said pipe and said secondhinge cylinder; a first hinge cap for tightly closing said second end ofsaid first hinge cylinder; and a first metal pipe inserted in said firstend of said first hinge cylinder, said first metal pipe having an innercircumferential surface coming into pressure contact with said firstgasket; and a second metal pipe inserted in said first end of saidsecond hinge cylinder, said second metal pipe having an innercircumferential surface coming into pressure contact with said secondgasket.
 4. A folding electronic device comprising: a first housinghaving an integrally formed, first hinge cylinder having a first end anda second end; a second housing having an integrally formed, second hingecylinder having a first end and a second end; a pipe inserted in saidfirst end of said first hinge cylinder and said first end of said secondhinge cylinder to connect said first housing and said second housing sothat said second housing is foldable with respect to said first housing;a wiring member inserted through said pipe to connect a first electroniccomponent mounted in said first housing and a second electroniccomponent mounted in said second housing; a first gasket providedbetween said pipe and said first hinge cylinder; a second gasketprovided between said pipe and said second hinge cylinder; a first hingecap for tightly closing said second end of said first hinge cylinder; athird hinge cylinder integrated with said first housing, said thirdhinge cylinder having a first end and a second end; a hinge modulehaving one end inserted in said second end of said second hinge cylinderand another end inserted in said first end of said third hinge cylinder;a third gasket provided between said hinge module and said second hingecylinder; and a second hinge cap for tightly closing said second end ofsaid third hinge cylinder.
 5. The folding electronic device according toclaim 4, further comprising a rib integrated with said first housing forengaging said hinge module to prevent removal of said hinge module fromsaid third hinge cylinder.
 6. The folding electronic device according toclaim 4, further comprising a hook fixed to said hinge module, said hookbeing engaged with said second hinge cylinder to prevent removal of saidhinge module from said second hinge cylinder.
 7. The folding electronicdevice according to claim 4, wherein said hinge module comprises: a caseinserted and fixed in said third hinge cylinder; a fixed cam plateaccommodated in said case; a movable cam plate inserted in said secondend of said second hinge cylinder so as to be nonrotatable relative tosaid second hinge cylinder; a plurality of balls held between said fixedcam plate and said movable cam plate; a connecting shaft for connectingsaid case and said movable cam plate; and a coil spring accommodated insaid case for biasing said fixed cam plate toward said movable camplate.
 8. The folding electronic device according to claim 7, whereinsaid hinge module further comprises an end cap for tightly closing anend portion of said case.
 9. The folding electronic device according toclaim 7, wherein said hinge module further comprises a waterproof hingecase for tightly closing an end portion of said case.
 10. A foldingelectronic device comprising: a first housing having an integrallyformed, first hinge cylinder having a first end and a second end; asecond housing having an integrally formed, second hinge cylinder havinga first end and a second end; a pipe inserted in said first end of saidfirst hinge cylinder and said first end of said second hinge cylinder toconnect said first housing and said second housing so that said secondhousing is foldable with respect to said first housing; a wiring memberinserted through said pipe to connect a first electronic componentmounted in said first housing and a second electronic component mountedin said second housing; a first gasket provided between said pipe andsaid first hinge cylinder; a second gasket provided between said pipeand said second hinge cylinder; and a first hinge cap for tightlyclosing said second end of said first hinge cylinder, wherein said firsthousing comprises a front case, a rear case joined to said front case, athird gasket interposed between joined surfaces of said front case andsaid rear case, and a plurality of screws for fixing said front case tosaid rear case; said screws being arranged outside of said third gasket.11. The folding electronic device according to claim 10, wherein saidfront case is formed of metal.
 12. The folding electronic deviceaccording to claim 11, wherein said rear case has an antennaaccommodating portion; said folding electronic device further comprisingan antenna accommodated in said antenna accommodating portion, and anantenna printed wiring board having a matching circuit connected to saidantenna; said antenna printed wiring board being spaced apart from saidmetallic front case by a given distance or more.
 13. The foldingelectronic device according to claim 1 A folding electronic devicecomprising: a first housing having an integrally formed, first hingecylinder having a first end and a second end; a second housing having anintegrally formed, second hinge cylinder having a first end and a secondend; a pipe inserted in said first end of said first hinge cylinder andsaid first end of said second hinge cylinder to connect said firsthousing and said second housing so that said second housing is foldablewith respect to said first housing; a wiring member inserted throughsaid pipe to connect a first electronic component mounted in said firsthousing and a second electronic component mounted in said secondhousing; a first gasket provided between said pipe and said first hingecylinder; a second gasket provided between said pipe and said secondhinge cylinder; and a first hinge cap for tightly closing said secondend of said first hinge cylinder, wherein said second housing comprisesa front case, a rear case joined to said front case, a third gasketinterposed between joined surfaces of said front case and said rearcase, and a plurality of screws for fixing said front case to said rearcase; said screws being arranged outside of said third gasket.
 14. Thefolding electronic device according to claim 13, wherein said front caseis formed of metal.
 15. A folding electronic device comprising: a firsthousing having an integrally formed, first hinge cylinder having a firstend and a second end; a second hinge cylinder having a wiring leadinghollow shaft, a first end, and a second end; a second housing engagedwith said wiring leading hollow shaft of said second hinge cylinder soas to be rotatable about said wiring leading hollow shaft; a pipeinserted in said first end of said first hinge cylinder and said firstend of said second hinge cylinder to connect said first housing and saidsecond housing so that said second housing is foldable with respect tosaid first housing; a wiring member inserted through said pipe toconnect a first electronic component mounted in said first housing and asecond electronic component mounted in said second housing; a firstgasket provided between said pipe and said first hinge cylinder; asecond gasket provided between said pipe and said second hinge cylinder;a first hinge cap for tightly closing said second end of said firsthinge cylinder; and a third gasket provided between said wiring leadinghollow shaft of said second hinge cylinder and said second housing. 16.The folding electronic device according to claim 15, wherein said wiringmember comprises a cable or a flexible printed wiring board.
 17. Thefolding electronic device according to claim 15, further comprising: afirst metal pipe inserted in said first end of said first hingecylinder, said first metal pipe having an inner circumferential surfacecoming into pressure contact with said first gasket; and a second metalpipe inserted in said first end of said second hinge cylinder, saidsecond metal pipe having an inner circumferential surface coming intopressure contact with said second gasket.
 18. The folding electronicdevice according to claim 15, further comprising: a third hinge cylinderintegrated with said first housing, said third hinge cylinder having afirst end and a second end; a hinge module having one end inserted insaid second end of said second hinge cylinder and another end insertedin said first end of said third hinge cylinder; a fourth gasket providedbetween said hinge module and said second hinge cylinder; and a secondhinge cap for tightly closing said second end of said third hingecylinder.